Signal in under water and surface * Volume: Approx. U/W : 115-125 dB. Surface : 125-130 dB * Heard range: Surface or Approx. over a 1.0 K. range. U/W Approx. 100 meters. * Type: AH-380-02 (ScubaPro Air-2, Tusa Duo-Air, and the Atomic SS1) * Clean in fresh water after use